In In-Si Situ u PC PCB B Dec echlo lorin inatio tion & - - PowerPoint PPT Presentation

In In-Si Situ u PC PCB B Dec echlo lorin inatio tion & n & De Degrad adatio ion w wit ith B Bio ioam amended GA GAC C

Kevin R. Sowers

Institute of Marine & Environmental Technology University of Maryland Baltimore County EPA ORD Webinar November 13, 2019

Advantages of Bioamended GAC

• Both sequesters & degrades PCBs
• Rapidly deployed and minimally invasive
• Minimal sediment disruption
• Reduced carbon footprint compared with other technologies
• No extensive waste management or habitat restoration

How Bioremediation of PCBs Works

Complementary activities of: 1) anaerobic halorespiring bacterium 2) aerobic oxidizing/dechlorinating bacterium

Why is Natural Attenuation of PCBs Slow?

Typical reduction in total mass of PCBs by MNA

Effect of Bioaugmentation

Halorespiration = 1st order rate kinetics Modeled effect of cell titer on halorespiration rate

• PCB dechlorinating population typically <103 cells mL−1
• Aqueous PCB concentrations too low to support large indigenous population
• Increasing cell number = increased rate

Lombard et al. 2014 ES&T 48, pp 4353–4360

Desorption Rate vs Dechlorination Rate

• PCB desorption rates exceed dechlorination rates of indigenous halorespiring populations
• Bioaugmentation increases dechlorination at rates similar to desorption rates

Needham et al. 2019 ES&T 53:7432-7441

Technology/Methodology Description

1) PCB anaerobic halorespirer and aerobic degrader available 2) Assays developed for monitoring treatment and bioamendments 3) Methods developed for biomass scale-up of bioamendments w/o PCB 4) System developed for in situ deployment of bioamendments on activated carbon agglomerate (SediMite)

Extraction

Bioamended Activated Carbon

• CLSM of SediMite™ loaded with PCB transforming microorganisms stained with SYBR green

Capozzi et al., 2019. Biofouling: 10.1080/08927014.2018.1563892

Application of Bioamended GAC

• various application methods available

Access road

Abraham’s Creek VA – April 2015

View from access road Corrugated steel culverts

• Abraham’s Creek MCBQ is an 8 acre/32,000 m2 watershed outflow
• Original contaminant likely Aroclor 1260
• Currently contaminated with an average 5 ppm PCB
• Treatments in four 400 sq. m plots
• Loading rate = 1 ton SediMite + 1012 cells/400 m2

Treatability Study-Results

• Bioamending with 105 cell/g yielded greatest reduction of PCBs after 375 days
• DF1 and LB400 were most robust bioamendments
• Addition of carbon source (cellulose) only slightly stimulated PCB degradation
• Mono- to nona-chlorobiphenyls were reduced = anaerobic & aerobic activity

Effect of Treatments with Depth

0.2 0.4 0.6 0.8 1 1 2 3 4 5 6 7 8 9 10 Homolog PPM PCB

10^5 LB400/DF1 D0 10^5 LB400/DF1 Top D120 10^5 LB400/DF1 Bottom D120

Channeling by benthic organisms

• Decrease in PCBs observed throughout 8 cm depth
• Bioturbation provided cycling of redox potential throughout sediment column

Field Test-Deployment

• 3000 kg SediMite deployed with modified venturi air mover
• Final SediMite concentration = 0.3g/10 g sediment
• Final bioamendment concentration = 106 cells/10 g sediment

Performance Assessment-Total PCBs

0 140 409 140 409

Plot 2 GAC Plot 1 Untreated

0 140 409 140 409

Plot 3 Plot 4 Bioamended GAC

• Significant decrease observed in both bioamended plots after 409 days
• 80% reduction in total mass of coplanar PCBs in plot 4
• No significant change in non-bioamended plots

Performance Assessment-Dissolved PCBs

0 140 409 140 409 0 140 409 140 409

Plot 2 GAC Plot 3 Plot 4 Bioamended GAC No Bioamendment Bioamendment Plot 1 Untreated

• Significant decrease observed in bioamended plots after 409 days
• Decrease with AC due to adsorption, but significantly less than bioamended plots
• No significant change in untreated plot or below 7.5 cm

Cost Comparison of Remediation Technologies

Treatment Alternative Total Capital Capitol Cost Cost ($/acre) (2017 dollars) Alt 1: No further action Alt 2: Monitored Natural Attenuation 130,000 16,666 Alt 3: Isolation cap 4,030,000 516,667 Alt 4: Excavation & on-site CDF 17,030,000 2,183,333 Alt 5: Excavate & off-site disposal 25,090,000 3,216,667 Alt 6: Partial excavation & off-site disposal 11,570,000 1,483,333 Alt 7: Capping and wetland creation 5,850,000 750,000 Alt 8: Reactive cap 4,030,000 516,667 Alt 9: SediMite™ only 1,096,720 140,605 Alt 10: Bioamended SediMite™ 1,767,920 226,656 Comparison of implementation of remediation technologies for 7.8 acre pond in Abraham’s Creek. Costs for Alt 1-8 are based on 2008 Feasibility Study for the site (Battelle 2008). Site-specific monitoring costs would be additional.

Other Treatment Sites

Baltimore Harbor MD

Primarily Aroclor 1260 contaminated sediment. Bioremediation resulted in an 80% decrease by mass of PCBs, from 8 to <2 mg/kg after 180 days. Status – treatability study

Waste Water Treatment Pond, Altavista VA

Aroclor 1248 contaminated sediment. Bioremediation resulted in an 80% decrease in mass of PCBs, from 275 to 49 mg/kg after 2.7 years. Status – ongoing pilot study.

South Wilmington Wetland Park, DE

Mouth of drainage outlet (14,150 sf) Completed May 2019 Status – full-scale treatment completed; monitoring results

Superfund River Sediments Southeast MI

Aroclor 1248 contaminated sediment. Bioremediation resulted in a 78 % decrease by mass of PCBs in 180 days and porewater PCB levels by 93%. Status – treatability study

Green Island, Kure Atoll, HI

Aroclor 1260 contaminated soil. Bioamended by spraying excavated soil that resulted in 48% decrease by mass of PCBs in 2.8 years. Status – full-scale treatment completed; monitoring results.

Anne Arundel County, MD.

Former laminate plant cooling pond (32,336 sf). Status: Full-scale treatment scheduled Spring 2020

Summary

• Bioamended AC reduces both the total mass and soluble fractions of PCBs
• Significant reduction in toxic equivalency (TEQ) of coplanar PCBs
• PCB transforming bacteria mix into sediments by natural bioturbation
• Different application methods available depending on site
• Well suited for environmentally sensitive sites, difficult to reach areas such as

under piers, water margins, dredged materials and sites where dredging or capping are not options

Acknowledgements

• Students & postdocs

Sonja Fagervold, Nathalie Lombard, Trevor Needham, Birthe Kjellerup, Rayford Payne

• Collaborators

Joel Baker (U. Washington), Hal May (MUSC), Chris Marshall (U. Pittsburgh), Brightfields Inc, Sediment Solutions LLC

• Sponsors

ESTCP (ER201215), NIEHS (5R01ES16197), ONR (N000140610090), SERDP (ER1492,1502, 2135)

• Contact Info

Kevin Sowers, sowers@umbc.edu; Upal Ghosh, ughosh@umbc.edu

Disclosure Statement: K. Sowers is a co-inventor of patents related to the technology for which he is entitled to receive royalties. The patents include U.S. Patent Nos. 6,946,248 and 7,462,480 B2 issued to the University of Maryland Baltimore County (UMBC) and Medical University of So. Carolina. and U.S. Patent No. 8,945,906 issued to UMBC. In addition, K. Sowers and U. Ghosh are partners in a startup company (RemBac Environmental) that has licensed the three technologies and is transitioning the technology to the field.